Cerebellar Tonsillar Herniation an Incidental Finding in Asymptomatic Patient

Cerebellar tonsillar herniation, often associated with Chiari malformation, involves the downward displacement of the cerebellar tonsils below the foramen magnum. This condition can lead to significant complications due to the limited intracranial space within the rigid skull. Timely diagnosis is crucial given its potentially fatal nature, with brain structural displacement evident on imaging studies. We present a case of a 27-year-old female with continuous headaches and dizziness, diagnosed with tonsillar herniation through MRI revealing 16 mm of tonsillar descent without associated hydrocephalus or syrinx. Tonsillar herniation, characterized by inferior descent of the cerebellar tonsils, may be congenital or acquired, with measurements typically referenced from the McRae line to the displaced tonsil tip. Complications include brainstem compression, obstruction of cerebrospinal fluid flow, syringomyelia, impaired blood flow, and various neurological and psychological symptoms. Management options vary based on symptom severity and may involve observation, medication, or surgical intervention to alleviate compression and improve cerebrospinal fluid flow. Consultation with a neurologist or neurosurgeon is essential for comprehensive evaluation and tailored management plans aiming to relieve pressure on the brainstem and spinal cord in tonsillar herniation cases.